Driving unit, exposure apparatus using the same, and device fabrication method

ABSTRACT

A driving unit includes an actuator for actuating a target and a magnetic dampener for controlling a vibration of the target, wherein the driving unit controls the vibration of the target, which is generated by the actuation of the actuator, by using the magnetic dampener.

The present application is a continuation of U.S. application Ser. No.10/827,882, filed Apr. 20, 2004, the contents of which is herebyincorporated by reference in its entirety.

This application claims priority benefits under 35 U.S.C. §119 based onJapanese Patent Application No. 2003-122115 filed on Apr. 25, 2003, andJapanese Patent Application No. 2004-110835 filed on Apr. 5, 2004, whichare hereby incorporated by reference herein in their entirety as iffully set forth herein.

BACKGROUND OF THE INVENTION

The present invention relates generally to fine driving units, and moreparticularly to units for finely adjusting the positions and tilts ofoptical elements, such as lenses or mirrors, used in exposureapparatuses for fabrication of semiconductor devices or liquid crystaldevices, etc. The present invention also relates to driving units forfinely adjusting the positions and tilts of the optical elements toacquire accurate imaging in relation to the projection exposing imagesof the original forms (masks or reticles, etc.) onto objects (wafers,etc.) and to the exposure apparatuses using the same. The driving unitaccording to this invention is not only applicable to exposureapparatuses which needs fine adjustment to the position and tilt of theoptical element, but also applicable to an apparatus, such as a samplestage of an electron microscope, which needs fine adjustment in vacuumstate to avoid dusts or specific outgas.

A semiconductor exposure apparatus transfers different kinds of patternson an original form (reticle) onto a silicon wafer (substrate). Besidesimproving resolution, it is also necessary to obtain overlay accuracyfor fabricating a high integrated circuit.

The propagation of vibrations from inside and/or outside the exposureapparatus to an optical element (mirrors and the like) in the exposureapparatus lowers the resolution and/or overlay accuracy. For example,vibrations from outside the exposure apparatus can be the vibration ofthe building where the exposure apparatus is installed. There are twokinds of vibration from inside the exposure apparatus. One is caused andpropagated to the optical element via a structure frame by operation ofa reticle stage. The other is caused and propagated to the opticalelement by operation of an actuator for adjusting the optical element.The actuator for adjusting the optical element (a target) should beoperated in two patterns to improve optical performance. The firstpattern should be relatively static, with the actuator operated betweenthe former exposure process and the latter exposure process. The secondpattern should operate the actuator during exposing. The second one mayhave problems with vibration caused and propagated to the opticalelement by the actuator. The vibration which is generated by operationof the actuator to move the target, such as a mirror, causes a biggerproblem, especially for EUV light (10 to 15 nm) used in an EUV exposureapparatus which has a shorter wavelength than KrF (248 nm) and ArF (193nm) used in a conventional exposure apparatus. To improve the resolutionand the overlay accuracy, a vibration controller for controlling thevibration by transforming vibration energy to other energies, such asheat energy, electrical energy, or mechanical energy, has been developed

Japanese Patent Application Publication No.11-233039 (JP11-233039)discloses a vibration controller using friction that can be used invacuum state.

Japanese Patent Application Publication No.11-044834 (JP11-044834)discloses an actuator, which has vibration controlling function usingthe squeeze-film effect of a viscous material 34, such as oil or grease.FIG. 12 shows sectional perspective view of the actuator with vibrationcontrolling functions using the viscous material 34 disclosed inJP11-044834. The actuator controls the output of a flange 32 byadjusting the pressure in a bellows 31 with a pressure controller (notshown). The actuator also controls the vibration by having the viscousmaterial 34 in a gap formed in a support member and arranged in thebellows 31. This can provide a clean unit, for example, for maintainingoutgas emitted from the viscous material 34 inside the bellows 31. Theactuator, depending on the inserting method of the viscous material 34,in addition to eliminating the influence of unwanted outgas, can be usedin vacuum state.

However, the method used in the vibration controller disclosed inJP11-233039 cannot be applied to an apparatus such as an EUV exposureapparatus which because the minute dust generated with the frictionlowers the performance of the EUV exposure apparatus, is easily troubledby a little dust.

The method described in JP11-044834 may cause aged deterioration in thevibration control effectiveness due to the influence of the frequentvibration.

BRIEF SUMMARY OF THE INVENTION

Accordingly, it is an exemplary object to provide a driving unit and anexposure apparatus which can be used in vacuum state, and use avibration control mechanism with small aged deterioration and stablevibration control effect.

A driving unit of one aspect according to the present invention includesan actuator for actuating a target and a magnetic dampener forcontrolling the vibration of the target, wherein the driving unitcontrols the vibration of the target, which is generated by theactuation of the actuator, by using the magnetic dampener.

The driving unit may further include a magnetic spring, wherein thedriving unit controls the vibration of the target by using the magneticspring and the magnetic dampener. The actuator may include apiezoelectric element.

The driving unit may include at least one first magnet fixed to thetarget, an additional weight located at a specific distance from thetarget, at least one second magnet having a polarity opposite to thefirst magnet and fixed to the additional weight to face the firstmagnet, and a conductor plate arranged between the first magnet and thesecond magnet. The conductor plate may be fixed to the target or theadditional weight. The conductor plate may be fixed to a fixing block,which is different from the target or the additional weight. Theconductor plate may include a cooling unit, which cools the target. Thecooling unit may cool the target by radiation. The cooling unit having aradiation element facing the target may cool the target by using theradiation element. The driving unit may include a Peltier device forcooling the radiation element.

The driving unit may include at least one third magnet fixed to thetarget and at least one fourth magnet arranged to be repellent to thethird magnet, wherein the fourth magnet is fixed to the additionalweight to face the third magnet.

The driving unit may include a bearing for joining the target and theadditional weight, wherein the bearing substantially maintains therelative positions between the target and the additional weight in aspecific direction.

The bearing may allow the target and the additional weight to move intwo directions, approximately perpendicular to the specific direction.The specific direction may be the same as the magnetic flux directionbetween at least one first magnet and at least one second magnet. Thebearing may include an elastic hinge. The bearing may include a pair ofpermanent magnets with the same polar facing each other. The bearing mayinclude a leaf spring. The bearing may include a ball bearing. Thebearing may include a hydrostatic bearing. A ventilator may be providedaround the hydrostatic bearing.

The driving unit may further include a magnetic flux generator forgenerating a magnetic flux in a first direction and a coil having astraight part along a second direction perpendicular to the firstdirection, wherein the driving unit controls the vibration of the targetin a third direction, which is perpendicular to both the first and thesecond directions.

The coil may be fixed to the target, and the magnetic flux generator maybe fixed to a structure supported independently from the target. Thecoil may include a first straight part and a second straight part inwhich current flows in a direction opposite to the flow direction in thefirst straight part, and the magnetic flux near the first straight partis substantially opposite to that near the second straight part.

The target may include an optical element. The optical element may be areflection element.

A vibration control block of another aspect according to the presentinvention includes a vibration control material inserted in a hollowpart. The vibration control material may have a dampening coefficient of10 to 10³ Ns/m. The vibration control block may be a flat shape. Thevibration control block may be a rotational symmetry shape. Thevibration control material may be any one of foamed rubber, gel, oil, orgrease.

A driving unit of still another aspect according to the presentinvention includes a vibration control block having a vibration controlmaterial inserted in a hollow part of the vibration control block.

A driving unit of still another aspect according to the presentinvention includes an actuator for actuating a target and a vibrationcontrol block with a vibration control material inserted in a hollowpart, wherein the driving unit uses the vibration control block tocontrol the vibration of the target. The vibration is generated by theactuation of the actuator.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit, which has an actuator for actuating atarget and a magnetic dampener for controlling a vibration of thetarget, wherein the driving unit uses the magnetic dampener to controlthe vibration of the target. The vibration is generated by the actuationof the actuator.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit arranged in a vacuum state, whereinthe driving unit has an actuator for actuating a target and a magneticdampener for controlling the vibration of the target, wherein thedriving unit uses the magnetic dampener to control the vibration of thetarget. The vibration is generated by the actuation of the actuator.

An exposure apparatus of still another aspect according to the presentinvention includes an illumination system for guiding light from a lightsource to a mask, a projection optical system for guiding the light fromthe mask to an object, wherein a driving unit controls the vibration ofa target included in the illumination optical system and a targetincluded in the projection optical system. The driving unit has anactuator for actuating the target and a magnetic dampener forcontrolling the vibration of the target, wherein the driving unit usesthe magnetic dampener to control the vibration of the target. Thevibration is generated by the actuation of the actuator.

The exposure apparatus may further include a light source emitting lightof 10 to 15 nm wavelengths.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit which has an actuator foractuating a target and a magnetic dampener for controlling the vibrationof the target, wherein the driving unit uses the magnetic dampener tocontrol the vibration of the target which is generated by the actuationof the actuator, and developing the object that has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit arranged in a vacuum state,wherein the driving unit has an actuator for actuating a target and amagnetic dampener for controlling the vibration of the target, where thedriving unit uses the magnetic dampener to control the vibration of thetarget which is generated by the actuation of the actuator, anddeveloping the object that has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising an illumination system for guiding a lightfrom a light source to a mask, a projection optical system for guidingthe light from the mask to an object, wherein a driving unit controlsthe vibration of a target included in the illumination optical systemand a target included in the projection optical system, the driving unithas an actuator for actuating the target and a magnetic dampener forcontrolling a vibration of the target, where the driving unit uses themagnetic dampener to control the vibration of the target which isgenerated by the actuation of the actuator, and developing the objectthat has been exposed.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit which has an actuator for actuating atarget, a magnetic dampener for controlling a vibration of the target,and a magnetic spring, wherein the driving unit controls the vibrationof the target, which is generated by the actuation of the actuator, byusing the magnetic spring and the magnetic dampener.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit arranged in a vacuum state, whereinthe driving unit has an actuator for actuating a target, a magneticdampener for controlling a vibration of the target, and a magneticspring, wherein the driving unit controls the vibration of the target,which is generated by the actuation of the actuator, by using themagnetic spring and the magnetic dampener.

An exposure apparatus of still another aspect according to the presentinvention includes an illumination system for guiding a light from alight source to a mask, and a projection optical system for guiding thelight from the mask to an object, wherein a driving unit controls avibration of a target included in the illumination optical system and atarget included in the projection optical system, wherein the drivingunit has an actuator for actuating a target, a magnetic dampener forcontrolling a vibration of the target, and a magnetic spring, whereinthe driving unit controls the vibration of the target, which isgenerated by the actuation of the actuator, by using the magnetic springand the magnetic dampener.

The exposure apparatus may further include a light source emitting lightof 10 to 15 nm wavelengths.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit which has an actuator foractuating a target, a magnetic dampener for controlling a vibration ofthe target, and a magnetic spring, wherein the driving unit controls thevibration of the target, which is generated by the actuation of theactuator, by using the magnetic spring and the magnetic dampener, anddeveloping the object that has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit arranged in a vacuum state,wherein the driving unit has an actuator for actuating a target, amagnetic dampener for controlling a vibration of the target, and amagnetic spring, wherein the driving unit controls the vibration of thetarget, which is generated by the actuation of the actuator, by usingthe magnetic spring and the magnetic dampener, and developing the objectthat has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising an illumination system for guiding a lightfrom a light source to a mask, and a projection optical system forguiding the light from the mask to an object, wherein a driving unitcontrols a vibration of a target included in the illumination opticalsystem and a target included in the projection optical system, whereinthe driving unit has an actuator for actuating a target, a magneticdampener for controlling a vibration of the target, and a magneticspring, wherein the driving unit controls the vibration of the target,which is generated by the actuation of the actuator, by using themagnetic spring and the magnetic dampener, and developing the objectthat has been exposed.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit which has an actuator for actuating atarget, a magnetic dampener for controlling a vibration of the target,at least one first magnet fixed to the target, an additional weightlocated at a specific distance from the target, at least one secondmagnet having a polarity opposite to the first magnet, and a conductorplate arranged between the first magnet and the second magnet, whereinthe driving unit controls the vibration of the target, which isgenerated by the actuation of the actuator, by using the magneticdampener, wherein the second magnet is fixed to the additional weight toface the first magnet.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit arranged in a vacuum state, whereinthe driving unit has an actuator for actuating a target, a magneticdampener for controlling a vibration of the target, at least one firstmagnet fixed to the target, an additional weight located at a specificdistance from the target, at least one second magnet having a polarityopposite to the first magnet, and a conductor plate arranged between thefirst magnet and the second magnet, wherein the driving unit controlsthe vibration of the target, which is generated by the actuation of theactuator, by using the magnetic dampener, wherein the second magnet isfixed to the additional weight to face the first magnet.

An exposure apparatus of still another aspect according to the presentinvention includes an illumination system for guiding a light from alight source to a mask, and a projection optical system for guiding thelight from the mask to an object, wherein a driving unit controls avibration of a target included in the illumination optical system and atarget included in the projection optical system, wherein the drivingunit has an actuator for actuating a target, a magnetic dampener forcontrolling a vibration of the target, at least one first magnet fixedto the target, an additional weight located at a specific distance fromthe target, at least one second magnet having a polarity opposite to thefirst magnet, and a conductor plate arranged between the first magnetand the second magnet, wherein the driving unit controls the vibrationof the target, which is generated by the actuation of the actuator, byusing the magnetic dampener, wherein the second magnet is fixed to theadditional weight to face the first magnet.

The exposure apparatus may further includes a light source emittinglight of 10 to 15 nm wavelengths.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit which has an actuator foractuating a target, a magnetic dampener for controlling a vibration ofthe target, at least one first magnet fixed to the target, an additionalweight located at a specific distance from the target, at least onesecond magnet having a polarity opposite to the first magnet, and aconductor plate arranged between the first magnet and the second magnet,wherein the driving unit controls the vibration of the target, which isgenerated by the actuation of the actuator, by using the magneticdampener, wherein the second magnet is fixed to the additional weight toface the first magnet, and developing the object that has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit arranged in a vacuum state,wherein the driving unit has an actuator for actuating a target, amagnetic dampener for controlling a vibration of the target, at leastone first magnet fixed to the target, an additional weight located at aspecific distance from the target, at least one second magnet having apolarity opposite to the first magnet, and a conductor plate arrangedbetween the first magnet and the second magnet, wherein the driving unitcontrols the vibration of the target, which is generated by theactuation of the actuator, by using the magnetic dampener, wherein thesecond magnet is fixed to the additional weight to face the firstmagnet, and developing the object that has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising an illumination system for guiding a lightfrom a light source to a mask, and a projection optical system forguiding the light from the mask to an object, wherein a driving unitcontrols a vibration of a target included in the illumination opticalsystem and a target included in the projection optical system, whereinthe driving unit has an actuator for actuating a target, a magneticdampener for controlling a vibration of the target, at least one firstmagnet fixed to the target, an additional weight located at a specificdistance from the target, at least one second magnet having a polarityopposite to the first magnet, and a conductor plate arranged between thefirst magnet and the second magnet, wherein the driving unit controlsthe vibration of the target, which is generated by the actuation of theactuator, by using the magnetic dampener, wherein the second magnet isfixed to the additional weight to face the first magnet, and developingthe object that has been exposed.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit which has an actuator for actuating atarget, a magnetic dampener for controlling a vibration of the target, amagnetic flux generator for generating a magnetic flux in a firstdirection, and a coil having a straight part along a second directionperpendicular to the first direction, wherein the driving unit controlsthe vibration of the target in a third direction perpendicular to boththe first and the second directions, which is generated by the actuationof the actuator, by using the magnetic dampener.

An exposure apparatus of still another aspect according to the presentinvention includes a driving unit arranged in a vacuum state, whereinthe driving unit has an actuator for actuating a target, a magneticdampener for controlling a vibration of the target, a magnetic fluxgenerator for generating a magnetic flux in a first direction, and acoil having a straight part along a second direction perpendicular tothe first direction, wherein the driving unit controls the vibration ofthe target in a third direction perpendicular to both the first and thesecond directions, which is generated by the actuation of the actuator,by using the magnetic dampener.

An exposure apparatus of still another aspect according to the presentinvention includes an illumination system for guiding a light from alight source to a mask, and a projection optical system for guiding thelight from the mask to an object, wherein a driving unit controls avibration of a target included in the illumination optical system and atarget included in the projection optical system, wherein the drivingunit has an actuator for actuating a target, a magnetic dampener forcontrolling a vibration of the target, a magnetic flux generator forgenerating a magnetic flux in a first direction, and a coil having astraight part along a second direction perpendicular to the firstdirection, wherein the driving unit controls the vibration of the targetin a third direction perpendicular to both the first and the seconddirections, which is generated by the actuation of the actuator, byusing the magnetic dampener.

The exposure apparatus may further includes a light source emittinglight of 10 to 15 nm wavelengths.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit which has an actuator foractuating a target, a magnetic dampener for controlling a vibration ofthe target, a magnetic flux generator for generating a magnetic flux ina first direction, and a coil having a straight part along a seconddirection perpendicular to the first direction, wherein the driving unitcontrols the vibration of the target in a third direction perpendicularto both the first and the second directions, which is generated by theactuation of the actuator, by using the magnetic dampener, anddeveloping the object that has been exposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising a driving unit arranged in a vacuum state,wherein the driving unit has an actuator for actuating a target, amagnetic dampener for controlling a vibration of the target, a magneticflux generator for generating a magnetic flux in a first direction, anda coil having a straight part along a second direction perpendicular tothe first direction, wherein the driving unit controls the vibration ofthe target in a third direction perpendicular to both the first and thesecond directions, which is generated by the actuation of the actuator,by using the magnetic dampener, and developing the object that has beenexposed.

A device fabricating method of still another aspect according to thepresent invention includes the steps of exposing an object by using anexposure apparatus comprising an illumination system for guiding a lightfrom a light source to a mask, and a projection optical system forguiding the light from the mask to an object, wherein a driving unitcontrols a vibration of a target included in the illumination opticalsystem and a target included in the projection optical system, whereinthe driving unit has an actuator for actuating a target, a magneticdampener for controlling a vibration of the target, a magnetic fluxgenerator for generating a magnetic flux in a first direction, and acoil having a straight part along a second direction perpendicular tothe first direction, wherein the driving unit controls the vibration ofthe target in a third direction perpendicular to both the first and thesecond directions, which is generated by the actuation of the actuator,by using the magnetic dampener, and developing the object that has beenexposed.

Other objects and further features of the present invention will becomereadily apparent from the following description of the preferredembodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a system for holding andadjusting an optical element using a parallel linked mechanism.

FIG. 2 is a whole view of an exposure apparatus with the mechanism forholding and adjusting the optical element installed.

FIG. 3 is a graph, which shows a specification of the optical element invibration.

FIG. 4 is a schematic perspective view of a system for holding andadjusting the optical element using a magnetic mass dampener.

FIG. 5 is a detailed view for explaining a magnetic spring.

FIG. 6 shows an elastic hinge.

FIG. 7 is a schematic perspective view of a system for holding andadjusting the optical element using a counter electromotive forcedampener.

FIG. 8 is an enlarged view of a coil and a magnet.

FIG. 9 shows an example of a repellent magnet structure.

FIG. 10 is a schematic perspective view of a system for holding andadjusting the optical element by applying the magnetic mass dampener inthe Z-direction.

FIG. 11 is a schematic perspective view of a system for holding andadjusting the optical element by applying the counter electromotiveforce dampener in Z-direction

FIG. 12 is a view of a driving unit using a conventional viscous elasticmaterial.

FIG. 13 is a schematic view of an elastic hinge according to the fifthembodiment.

FIG. 14 is a flowchart for explaining a method for fabricating devices(semiconductors like IC, LSI, LCD, CCD, etc).

FIG. 15 is a detailed flowchart for Step 4 of the wafer process shown inFIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A magnetic dampener used in a driving unit according to the presentinvention is a dampener that includes a magnetic circuit made of amagnet, and a conductor. The magnetic dampener applies a vibrationcontrolling force which has an effect opposite to the moving directionand proportional to the moving velocity of the conductor's traversal inan electromagnetic field (see Collective Treatise of The Japan Societyof Mechanical Engineering, C compilation, Vol. 56, No. 525, 1990,p1079-).

“Vibration controlling” uses two types of control method. One is activecontrol of vibration using a controller or the like and the othertransforms the vibration energy to other energy, such as heat energy,electrical energy, and mechanical energy. The vibration control meansused in this application is the latter type.

The First Embodiment

FIG. 2 is a whole view of an exposure apparatus with an adjustmentmechanism 8 installed, which has a holding member 3 for an opticalelement 1 and a driving unit.

The exposure apparatus is, for example, a reduction projection exposureapparatus (EUV exposure apparatus) using Extreme Ultra Violet light (EUVlight) with wavelengths of 10 to 15 nm shorter than ultraviolet light.To prevent the absorption of the EUV light by gas, the inside of theexposure apparatus using the EUV light should maintain a pressure of 100Pa or smaller, preferably 10⁻⁴ Pa or smaller, for the path of the EUVlight. The exposure apparatus includes a light emission unit (notshown), an illumination optical system for illuminating a reticle withthe light from the light emission unit (not shown), a reflection-typeprojection optical system for guiding the light from the reticle onto awafer (it is preferable that construction be with reflection opticalelements only). A system 9 for holding and adjusting the optical elementaccording to the present invention is arranged in the projection opticalsystem or the illumination optical system. The system 9 holds andadjusts an optical element 1 (herein a mirror) so that the projectionoptical system or the illumination optical system satisfies thepreferable optical specification (or so that the aberration of theoptical system is at a specific value).

In FIG. 2, a structure frame 24 is installed on a floor 22 via avibration isolator 23 to support a mirror barrel 25 of the projectionoptical system. Although, the structure frame 24 only supports theprojection optical system in FIG. 2, it may also support theillumination optical system or both the illumination optical system andthe projection optical system.

FIG. 1 shows an example of the system 9 for holding and adjusting theoptical element. An intermediate block 2, holding the optical element 1as a target with three holding members 3, can be position and tiltcontrolled by the adjustment mechanism 8. Therefore, the position andtilt of the optical element 1 can be adjusted with the adjustmentmechanism.

Here, the gravity center of the triangle formed with the three holdingmembers 3 and the gravity center of the optical element 1 areapproximately the same except, as explained before, for a component ofthe gravity center in the direction perpendicular to a plane formed bythe triangle. This makes it possible to distribute the mass of theoptical element approximately evenly to the three holding members.

The adjustment mechanism 8 used in this embodiment is, for example, ageneral bipod-type parallel-linked mechanism with an elastic hinge 5, anactuator 4, etc. The parallel linked mechanism can move (or control theposition and tilt of) a movable part 7 (herein, the intermediate block2, the holding member 3, and the optical element 1) against a fixedblock 6 in six degrees of freedom by actuating (or expanding andcontracting) six actuators 4 independently. The actuator 4 generallyuses a laminated piezoelectric element. It may also use a linear motor,a liquid actuator-like cylinder with bellows, or a motor. The structureof the adjustment mechanism is not limited in this embodiment. It mayuse other structures which can adjust (if possible, at least in fivedegrees of freedom, preferably in six degrees of freedom) the positionand tilt of the intermediate block 2. For example, an enlargingmechanism or a reduction mechanism is provided in accordance with theadjustment movement and resolution demanded on the optical element 1 tobe adjusted because the output displacement is small in cases where theactuator 4 uses the laminated piezoelectric element. Meanwhile, thevibration from outside the exposure apparatus shakes the optical element1, which is mechanically engaged to the floor 22. In this case, theoptical performance of the whole optical system may be lowered dependingon the amplitude of the optical element's vibration.

FIG. 3 shows a simulation result of vibration (frequency vs. amplitude)of one optical element 1 when, for example, 10 gal (0.1 m/s²) ofacceleration is added to the floor 22 shown in FIG. 2. In addition toconsidering a composed spring constant of the adjustment mechanism 8 andholding member 3, and the weight of the adjustment mechanism 8 and theholding member 3, the calculation has been executed on the assumptionthat a natural frequency of the whole system for holding and adjustingthe optical element is approximately 150 Hz and the dampening factor is0.05. FIG. 3 shows that the optical element 1 oscillates with itsnatural frequency (approximately 150 Hz) in about 70 nm of amplitude.One of the following countermeasures will be needed if the amplitudeallowance of the optical element 1 is smaller than this value.

1. To decrease the disturbing vibration from the floor 22.

2. To control the disturbing vibration by the vibration isolator(dampener) 23.

3. To increase the natural frequency of the system 9 for holding andadjusting the optical element.

4. To add dampeners to increase the dampening factor of the system 9 forholding and adjusting the optical element.

Method 4 “To add dampeners to increase the dampening factor of thesystem 9 for holding and adjusting the optical element” is elected inthe first embodiment.

Use of a vibration control rubber including gel, an air spring, andfriction for dampening of a mechanical structure is well known. However,all of them cannot be used because of dust generation, existence ofdegas inadequate for the exposure apparatus, and inadaptability tovacuum state. Enclosing materials which generate dust or degas into thebellows does not solve the problem of degradation or aged deteriorationfrom abrasion of materials like rubber, thus increasing assemblingprocess and parts.

Accordingly, this embodiment uses a dynamic dampener (mass dampener) fordampening the vibration. The dynamic dampener is a combination of amagnetic spring which utilizes a restoring force from magnets arrangedto attract each other via a bearing, and a magnetic dampener whichinserts a conductor plate in a gap between the magnets and utilizes aneddy current proportional to the moving speed of the magnetic field. Theconductor plate may be fixed to the optical element (the target), to theadditional weight, to the fixed block 6, and to the floor 22.

FIG. 4 shows the dynamic dampener using the magnetic spring 36 and themagnetic dampener applied to the system 9 for holding and adjusting theoptical element shown in FIG. 1. To compose the dynamic dampener, aplurality of (herein, three) bearings 12 is used for the intermediateblock 2, and the magnet 13 is fixed onto the additional weight 11 whichis supported by the intermediate block 2. The magnet 13 is also fixed onthe intermediate block 2 so that the magnet 13 on the additional weightattracts each other. The bearing 12, explained before, substantiallylimits the additional weight 11 from moving relative to the intermediateblock in the Z direction (direction approximately perpendicular to theoptical element), but does not limit movement in the X, Y directions.However, the additional weight can move slightly in the Z direction whenmoving relative to the intermediate block in X, Y directions. Becausethe bearing shown in FIG. 6 may cause slight movements in the Zdirection when there are movements in the X, Y directions, the slightmovement in the Z direction is within the scope of this embodiment. Themagnetic spring 36 generates the restoring force according to thedisplacement of the additional weight 11 which moves relative to theintermediate block 2 in XY plane. The conductor 10 supported by thefixed block 6 is arranged in the gap between the magnet 13 that is fixedon the additional weight 11 and on the intermediate block 2. Thus, themagnetic dampener controls the vibration of the intermediate block (theoptical element) with the eddy current generated by the relativemovement of the additional weight 11.

Moreover, the dampener explained in this embodiment works to control thetotal vibration in the XY plane of the intermediate block 2, the holdingmechanism, and the optical element 1, but hardly moves in the Zdirection.

The spring constant k2 and the dampening ratio of the magnetic dampenerζ2 in additional systems using the magnetic spring 36 as the designequation of the dynamic dampener are described respectively:$\begin{matrix}{k_{2} = {k_{1}\frac{\mu}{\left( {1 + \mu} \right)^{2}}}} & (1) \\{Ϛ_{2} = {\sqrt{\frac{3\mu}{8\left( {1 + \mu} \right)}} = \frac{c_{2}}{2\sqrt{m_{2}k_{2}}}}} & (2)\end{matrix}$

Herein, k1 is the rigidity of the system 9 for holding and adjusting theoptical element; μ is a ratio of a weight m2 of the additional weight 11and a total weight m1 of the intermediate block 2, the holdingmechanism, and the optical element 1, i.e. (μ=m2/m1); C2 is a dampeningcoefficient of the magnetic dampener. C2 can be described as follows,where B is a magnetic flux density in the gap of the magnet, V is avolume of the conductor in magnetic flux, ρ is a resistance of theconductor, and CO is a correction coefficient. $\begin{matrix}{c_{2} = {\frac{B^{2}V}{\rho}C_{0}}} & (3)\end{matrix}$

Seto already estimated a correction coefficient Co (see CollectiveTreatise of The Japan Society of Mechanical Engineering, C compilation,Vol. 56, No. 525, 1990, p1079-), as follows:C ₀=1−e ^(−0.15α)  (4)

Here, α is a ratio described α=(area of the conductor)/(area of amagnetic pole). It is valid in the range of 2<α<5. Parameters aredecided using the above equations.

Optical elements such as a reflection mirror may be deformed due to heatenergy absorption from the exposure light in the exposure apparatus. Tolower the influence of heat deformation to the optical element 1 fromthe exposure energy, the optical element 1 should be cooled. To cool theoptical element 1, the conductor plate 10 could be used as a coolingdevice. For example, the conductor plate is used as a radiation plate tocool the optical element 1 or the intermediate block. In this case, theconductor plate 10 is cooled by a Peltier device or liquid coolant. Whenusing coolant, it is preferable that pipes are installed for the flowpath of the coolant.

FIG. 5 shows a detailed description of a part of the vibration controlstructure in the system 9 for holding and adjusting the optical elementshown in FIG. 4. The target includes not only the intermediate block 2or the holding member 3 shown in FIG. 5, but also the optical element 1.The annular shaped intermediate block 2 fixes, for example, a total oftwelve block magnets 13 on its circumference. The surface polarities “N”and “S” of the magnets 13 are described in FIG. 5. (The polarities ofhidden magnets are not shown). The number of the magnets 13 should be aneven number but is not limited to twelve. The number should be four orgreater, but preferably twelve or more. A magnetic material ispreferable for the intermediate block 2 because it can also be a yoke(an element forming a closed magnetic path). If the intermediate block 2is a non-magnetic material, the yoke, made of a magnetic material,should be inserted between the magnets 13 and the intermediate block 2.The magnet 13 should be adhered to the intermediate block 2 using anadhesive. The degas from the adhesive which is inappropriate for theenvironment of the exposure apparatus should be shielded so as not toleak out to the optical element's 1 space. The magnets 13 may also befixed by screws by forming counter borings in the magnets 13.

The same number of magnets 13 that were fixed on the intermediate block2 is also fixed onto the additional weight 11. Preferably, theadditional weight 11 is made of a magnetic material, however, if it ismade of a non-magnetic material, a yoke made of a magnetic materialshould be inserted between the magnets 13 and the additional weight 11.

The bearing 12 is provided between the intermediate block 2 and theadditional weight 11. The bearing 12 does not limit (because of lowrigidity) the relative movement of the intermediate block 2 and theconductor plate 10 in the XY plane, but limits movement (because of highrigidity) in the Z direction. That is, the bearing 12 maintains anapproximately constant gap between the intermediate block 2 and theconductor plate 10 to prevent the gap between the intermediate block 2and the conductor plate 10 from changing (mainly decreasing) due to thesuction force of the magnets 13. The bearing 12 uses for example anelastic hinge, a ball bearing, or a hydrostatic bearing. The elastichinge may combine two bearings whose shape are shown in FIG. 6A and FIG.6B (the shape being substantially deformable in one direction), may usea bearing that is rotationally symmetrical as shown in FIG. 6C, or mayuse a combination of a leaf spring (not shown). In cases where thebearings are combined as shown in FIG. 6A and FIG. 6B, it is preferableto combine two bearings so that the deformable direction crossesperpendicularly.

Deformation for buckling of the magnets 13 should be considered whenusing the elastic hinge as the bearing 12 shown in FIGS. 4 and 5. Whenthe weight of the movable part (the target) is relatively light and thenatural frequency of the movable part is relatively low (for example, afew tens Hz), a total spring constant of an additional spring whichforms the mass dampener (the magnetic spring 36 and the elastic bearingin XY directions in this case) should be small. Also, it is also noteasy to have both high rigidity in the Z direction, enough to resist forthe suction force of the magnets, and low rigidity in the XY directions.So, it is preferable to use both the elastic bearing 12 and repellentmagnets (magnets 13 are arranged between the intermediate block 2 andthe additional weight 11 so they face one another to generate repellentforce). In FIG. 5, the magnets for repellent whose polarities areindicated with circles (the magnets whose polarities are indicatedwithout circles are attracting each other) are arranged in four portionsand balanced according to the gravity center of the movable part 7.Instead of three magnets of the same polarities arrayed in a series onthe intermediate block as in this case, one large magnet 13 can bearranged. The arrays of the magnets 13 on the intermediate block 2 andthat on the additional weight 11 are exchangeable. The rigidity in Zdirection is maintained by arranging eight pairs of magnets forattracting each other and four pairs of magnets for repelling each otherbetween the intermediate block and the additional weight in thisembodiment shown in FIG. 5. However, the number and combination ofmagnets may be changed in accordance with the weight of the movable partor the natural frequency of the target.

The repellent force can be generated with a total of three magnets 13 asshown in FIG. 9. Though the intermediate block 2 fixes one magnet 13 andthe additional weight 11 fixes two magnets 13 in FIG. 9, thearrangements of the magnets on the intermediate block 2 and that on theadditional weight 11 are changeable. The bearing 10 can use thehydrostatic type in non-vacuum state. In the EUV exposure apparatus (notshown), which is mainly explained in this embodiment, a step-shapedventilation should be provided around the hydrostatic bearing. The fixedblock supports the conductor plate 10 in this case.

Accordingly, the system 9 for holding and adjusting the optical elementcan compactly arrange the mass dampener and obtain high accuracypositioning.

This embodiment can control the vibration of the optical element l (thetarget), caused by the drive of the actuator 4 for positioning andaligning the optical element 1 (the target), by using the magnetic massdampener shown in FIG. 4.

It can also control the vibration of the optical element 1 (the target)caused by vibrations from outside the exposure apparatus, such as thevibration from the building where the exposure apparatus is installed,by using the magnetic mass dampener shown in FIG. 4.

Additionally, by using the magnetic dampener as shown in FIG. 4, it canstably control the vibration with little age deterioration and preventdecrease of the EUV light due to degas or dust.

The Second Embodiment

FIG. 7 shows a system 9 for holding and adjusting the optical elementwhich includes a drive unit according to the second embodiment of thepresent invention.

The method 4 “To add the dampener for increasing the dampening factor ofthe system 9 for holding and adjusting the optical element” is electedin this embodiment. This is the same as in the first embodiment. Adampener using back electromotive force is applied to the system 9 forholding and adjusting the optical element will be explained later.

A voltage e generated in crossing a coil in a specific magnetic field isdescribed as:e=nBl{dot over (x)}  (5)

Here, n is a turn of the coil, B is a magnetic flux density at thecoiled position, 1 is an effective length of the coil, and {dot over(x)} is a moving speed of the coil.

According to the equation (5), the current i which flows in the coil isdescribed using R as an internal resistance as follows: $\begin{matrix}{i = \frac{{nBl}\overset{.}{x}}{R}} & (6)\end{matrix}$

The force F by the current to the coil is described as follows:$\begin{matrix}{F = \frac{({nBl})^{2}\overset{.}{x}}{R}} & (7)\end{matrix}$

Therefore, by appropriately deciding the above parameters in accordancewith the apparatus, the dampening coefficient can be controlled.

FIG. 7 shows an example concerning this. A driving unit in this examplearranges a vibration control plate 16, supported to the intermediateblock 2, via the bearing, for generating dampening force in the XYplane. The intermediate block 2 and the vibration control plate 16 areconnected approximately rigid.

The coil 14, provided on the vibration control plate 16, is arranged inthe gap between the pairs of magnets 13, which are supported by thefixed block 6. The magnets 13 are arranged to face and attract eachother. Preferably, the coil 14 is an ellipse having two straight parts.For example, it may be a combination of two semi-circle and two straightlines, or four quarter-circle and four segments with the rectangularcorners rounded. In this case, it is preferable that the straight partfaces the circumferential direction of the optical element (thetangential direction of the circle if the optical element in thisembodiment is of circular shape). By crossing the magnetic flux of themagnets 13 facing each other perpendicularly with the straight part ofthe coil 14 can generate force to the radial direction (the directionperpendicular to magnetic flux direction and circumferential directionof the optical element) of the optical element as the target and controlthe vibration. A total of six coils 14 are arranged evenly at threecircumferential positions on each surface of the vibration control plate16. However, the coils 14 may be arranged at different positions whenthe number of coils 14 changes or only on one surface of the vibrationcontrol plate 16 to shorten the gap of the magnets 13. The positions ofthe coils 14 and the magnets 13 may also be changed. For example, thecoil 14 may be supported by the fixed block 6 and may be arranged in thegap between the magnets 13 that are fixed on the vibration control plate16 and on the intermediate block 2 to face each other.

FIG. 8 is an enlarged view of a part of the magnet 13 and the coil 14.The magnets 13 having different polarities are preferably arranged atthe positions corresponding to two straight parts of the coil 14. Inother words, in a direction approximately opposite where the magneticflux is generated and at positions corresponding to two straight partsof the coil 14.

Accordingly, the system 9 for holding and adjusting the optical elementcan arrange the dampener compactly and obtain high accuracy positioning.

This embodiment can control the vibration of the optical element 1 (thetarget) caused by the drive of the actuator 4, used for positioning andaligning the optical element 1 (the target), by using the counterelectromotive force dampener as shown in FIG. 7.

It can also control the vibration of the optical element 1 (the target)caused by the vibration from outside of the exposure apparatus, such asthe vibration of the building where the exposure apparatus is installed,by using the counter electromotive force dampener shown in FIG. 7.

Additionally, it can stably control the vibration with little agedeterioration and prevent decrease of the EUV light caused by the degasor dust, by using the counter electromotive force dampener shown in FIG.7.

The Third Embodiment

Referring now to FIG. 10, a description will be given of a driving unitof the third embodiment according to the present invention. The firstembodiment and the second embodiment mainly provide dampening force inthe XY plane. The third embodiment will describe a method for providingthe dampening force in the Z direction. This embodiment combined withthe first and/or the second embodiment can provide the dampening forcein both the XY and Z directions.

FIG. 10 shows a mass dampener for dampening in the Z direction of thisembodiment. The description of the mass dampener's principle, which isthe same as explained in the first embodiment, will be omitted.

An additional weight 11 is cylindrical shape and is arranged outside theintermediate block 2 [further from the optical axis of the opticalelement (as a target) than the intermediate block] in this embodiment.Preferably, the additional weight 11 uses a magnetic material as a yoke.The magnets 13 are arranged to attract each other in the gap between theintermediate block 2 and the additional weight 11. Though the magnets 13are described in the FIG. 10 as rectangular shape, they may havecylindrically curved surfaces in order to fit the cylindrically curvedsurface of the additional weight 11. The magnets 13 are preferablyarranged evenly on the circumference. In this embodiment, three pairs ofmagnets 13 were evenly arranged at 120 degree with each centering theoptical axis of the optical element.

A leaf spring 17 supports the cylindrical shaped additional weight 11around the intermediate block 2, keeps the gap between the magnets 13,and maintains the degree of freedom in the Z direction. The preferabledesign is to have the sum of the rigidity of the leaf spring 17 in the Zdirection and the rigidity generated by the magnetic springapproximately satisfy the equation (1). Preferably, the leaf springs 17are evenly arranged on the circumference, and may be fixed to both thesurfaces of the additional weight 11 and the intermediate block 2.

A conductor plate 10, in the gap between the magnets 13 and supported bythe fixed block 6, provides the dampening force for generating eddycurrent with relative movement to the additional weight 11 on theintermediate block 2.

Accordingly, the system 9 for holding and adjusting the optical elementcan compactly arrange the dampener and obtain high accuracy positioning.

This embodiment can control the vibration of the optical element 1 (thetarget), caused by the drive of the actuator 4 for positioning andaligning the optical element 1 (the target), by using the magnetic massdampener shown in FIG. 10.

It can also control the vibration of the optical element 1 (the target),caused by the vibration from outside of the exposure apparatus, such asthe vibration of the building where the exposure apparatus is installed,by using the magnetic mass dampener shown in FIG. 10.

Additionally, it can stably control the vibration with little agedeterioration and prevent decrease of the EUV light caused by the degasor the dust, by using the magnetic mass dampener as shown in FIG. 10.

The Fourth Embodiment

Referring now to FIG. 11, a description will be given of a driving unitof the fourth embodiment according to the present invention. The firstembodiment and the second embodiment provide the dampening force mainlyin the XY plane. The fourth embodiment will describe another method forproviding the dampening force in the Z direction. This embodimentcombined with the first and/or the second embodiment can provide thedampening force in both the XY and Z directions.

FIG. 11 is a schematic perspective view of a system 9 for holding andadjusting the optical element with a dampener which uses counterelectromotive force for dampening in the Z-direction of this embodiment.The description of the principle of the dampener using the counterelectromotive force and the detailed structure according to the dampenerusing the counter electromotive force will be omitted because it wasexplained before in the second embodiment.

In this embodiment, a movable coil 14 is arranged on a vibration controlplate 16, which is installed to an intermediate block 2. Preferably, themovable coil 14 is an ellipse with a straight part. The straight part ispreferably arranged to perpendicularly cross the Z direction in atangent direction. The coil 14 may be provided on both surfaces of thevibration control plate. Also, preferably, a plurality of the coil 14 isarranged evenly on the circumference of the intermediate block 2. Onevibration control plate 16 may function as a plurality.

The magnets 13 on the fixed side, for example, are supported by thefixed block 6. A pair of magnets 13 is arranged around both sides of thecoil 14 to attract each other. Detailed description for installation ofthe magnet 13 is approximately the same as in FIG. 8. The magnet shouldbe arranged so that the magnetic flux direction around one side of thestraight part of the coil 14 is opposite to that around the other sideof the straight part of the coil 14.

Accordingly, the system 9 for holding and adjusting the optical elementcan compactly arrange the dampener and obtain high accuracy positioning.

The exposure apparatus shown in FIG. 2, which has the optical element asthe target and is supported by the driving unit described in the firstto the third embodiments to control vibration, can also apply thedriving unit of this embodiment. An illumination optical system whichapproximately illuminates a mask (or a reticle) evenly with light fromthe light source is not shown in FIG. 2. However, the illuminationoptical system can include the driving unit of this embodiment. Needlessto say, a projecting optical system which guides the light from the maskto a wafer (an object) may include the driving unit of this embodiment.

This embodiment can control the vibration of the optical element 1 (thetarget), caused by the drive of the actuator 4 for positioning andaligning the optical element 1 (the target), by using the counterelectromotive force dampener as shown in FIG. 11.

It can also control the vibration of the optical element 1 (the target),caused by the vibration from outside of the exposure apparatus, such asthe vibration of the building where the exposure apparatus is installed,by using the counter electromotive force dampener shown in FIG. 11.

Additionally, it can stably control vibration with little agedeterioration and prevent decrease of the EUV light caused by the degasor the dust, by using the counter electromotive force dampener as shownin FIG. 11.

The Fifth Embodiment

Magnetic vibration control methods for the adjustment mechanism of theoptical element by using parallel mechanisms were explained in the firstto fourth embodiment. A vibration control block having an elastic hingestructure shown in FIG. 13 is used for the dampening method of thestructure shown in FIG. 4. The elastic hinge as shown in FIG. 13 is arod, which is narrowed at approximately the center of the longitudinaldirection by cutting, can deform elastically at the narrowed portion.The elastic hinge has an approximately rotational symmetrical shapecentering a specific axis and can be deformed in any directionperpendicular to the longitudinal direction of the elastic hinge.

A pit whose direction agrees with the rotational symmetrical axis isformed in the elastic hinge. A vibration control material 35 is insertedin the pit and is shielded by means of welding or the like. The elastichinge does not function only as a spring, but also as a dampener.Mechanical dampening which can be used in vacuum state and hardlygenerates dust or degas (substantially no dust and no degas) can berealized with use of the elastic hinge as a connecting mechanism forparallel mechanism etc., for connecting the intermediate block 2 and theadditional weight 2 as shown in FIG. 4 or FIG. 10, and for connectingthe intermediate block 2 and the vibration control plate 16 as shown inFIG. 7 or FIG. 11.

The number of the pit formed in the elastic hinge may be one or more.The pit does not need to penetrate. One non-penetrating pit may beformed in the elastic hinge.

This invention will be effective when the longitudinal length of thenon-penetrating pit is ¼ or more of the elastic hinge.

The longitudinal direction is a normal direction of the pit.

The pit may be a cylindrical shape as in FIG. 13 or a polygon pillarshape.

The elastic hinge may be pillar shaped as shown in FIG. 6A and FIG. 6B,instead of the rotational symmetrical shape shown in FIG. 13 and FIG.6C. The leaf spring type elastic hinge may be holed, filled withvibration control material 35 in the hole, and plugged to shield thevibration control material 35. Preferably, the vibration controlmaterial 35 is preferably completely encased. The vibration controlmaterial can use foam rubber, gel, oil, grease, or any other materialused in dampener steel.

The vibration control material may have a damping coefficient of 10 to10³ Ns/m, preferably 30 to 500 Ns/m.

The elastic hinge may be used in conjunction with the magnetic dampenersdescribed in the first to the fourth embodiment, or may be used insteadof the magnetic dampeners described in the first to the fourthembodiment.

The vibration control method using the shielded vibration controlmaterial 35 does not apply only to the elastic hinge explained before,but also applies to a block for vibration control or to various shapessuch as a stick. For example, the compact dampener can utilize thevibration control material 35 not only to the part of the elastic hingeexplained before, but also to the block arranged on both sides of theelastic hinge. However, the design should take into consideration thedecrease of mechanical strength of the element when it's hollowed.

Referring now to FIGS. 14 and 15, a description will be given of anembodiment of a device fabricating method using the above exposureapparatus as shown in FIG. 2. FIG. 14 is a flowchart for explainingfabrication of devices (i.e., semiconductor chips such as IC and LSI,LCDs, CCDs, etc.). Here, as an example, a description will be given of asemiconductor chip fabrication. Step 1 (circuit design) designs asemiconductor device circuit. Step 2 (mask fabrication) forms a maskhaving a designed circuit pattern. Step 3 (wafer preparation)manufactures a wafer using materials such as silicon. Step 4 (waferprocess), referred to as a pretreatment, forms the actual circuitry onthe wafer through photolithography using the mask and wafer. Step 5(assembly), also referred to as a posttreatment, forms the wafer fromStep 4 into a semiconductor chip and includes an assembly step (e.g.,dicing, bonding), a packaging step (chip sealing), and the like. Step 6(inspection) performs various tests on the semiconductor device made inStep 5, such as validity test and durability test. Through these steps,a semiconductor device is finished and shipped (Step 7).

FIG. 15 is a detailed flowchart of the wafer process in Step 4. Step 11(oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms aninsulating film on the wafer's surface. Step 13 (electrode formation)forms electrodes on the wafer by vapor disposition and the like. Step 14(ion implantation) implants ion into the wafer. Step 15 (resist process)applies a photosensitive material onto the wafer. Step 16 (exposure)uses the exposure apparatus to expose a circuit pattern on the mask ontothe wafer. Step 17 (development) develops the exposed wafer. Step 18(etching) etches parts other than a developed resist image. Step 19(resist stripping) removes unused resist after etching. These steps arerepeated to form multilayer circuit patterns on the wafer. The devicefabrication method of this embodiment may manufacture higher qualitydevices than the conventional one. Accordingly, the device fabricatingmethod and the devices as products are also within the scope of thepresent invention.

As explained above, the first to fifth embodiment according to thepresent invention can provide a clean, no degas and dust, driving unitthat can be arranged compactly in an apparatus installed in vacuumstate. Therefore, the target can be accurately positioned.

This invention controls the vibration of the target generated by theactuation of the actuator by using a magnetic damper.

Further, the present invention is not limited to these preferredembodiments. Various variations and modifications may be made withoutdeparting from the scope of the present invention.

1. A driving unit comprising: an actuator for actuating a target; and amagnetic dampener for controlling a vibration of the target, whereinsaid magnetic damper includes: a conductor plate fixed to one of thetarget and a structure that is supported movable to the target; and amagnet fixed to the other of the target and the structure to face theconductor plate, and wherein said magnetic damper controls the vibrationof the target generated by a driving of the actuator using a dampingforce that is effected when the conductor plate crosses a magnetic fieldof the magnet.
 2. A driving unit according to claim 1, furthercomprising a magnetic spring, wherein the driving unit controls thevibration of the target by using the magnetic spring and the magneticdamper.
 3. A driving unit according to claim 1, wherein the actuatorcomprises a piezoelectric element.
 4. A driving unit according to claim1, further comprising: a magnetic flux generator for generating amagnetic flux in a first direction; and a coil having a straight partalong a second direction perpendicular to the first direction, whereinsaid driving unit controls the vibration of the target in a thirddirection perpendicular to both the first and the second directions. 5.A driving unit according to claim 4, wherein the coil is fixed to thetarget, and the magnetic flux generator is fixed to a structuresupported independently from the target.
 6. A driving unit according toclaim 4, wherein the coil comprises a first straight part and a secondstraight part in which a current flow in a direction opposite to theflow direction in the first straight part, and the magnetic flux nearthe first straight part is substantially opposite to that near thesecond straight part.
 7. A driving unit according to claim 1, whereinthe target comprises an optical element.
 8. A driving unit according toclaim 4, wherein the optical element is a reflection element.
 9. Adriving unit comprising: an actuator for actuating a target; and avibration control block having a vibration control material inserted ina hollow part, wherein the driving unit controls the vibration of thetarget, which is generated by the actuation of the actuator, by usingthe vibration control block.
 10. A vibration control block according toclaim 9, wherein the vibration control material has a dampingcoefficient of 10 to 10³ Ns/m.
 11. A vibration control block accordingto claim 9, wherein the vibration control block is a flat shape.
 12. Avibration control block according to claim 9, wherein the vibrationcontrol block is a rotational symmetrical shape.
 13. A vibration controlblock according to claim 9, wherein the vibration control material isany one of foam rubber, gel, oil, or grease.